(1) Field of the Invention
The invention refers to an apparatus for advancing single sacks from a support to a filling station comprising a charging funnel, said appartus comprising a conveying means having suction devices for the opening and gripping of the sacks, and a pulling up device for pulling up the sack to said charging funnel arranged behind said conveying means.
(2) Description of the Prior Art
In presently known apparatuses the sacks are mostly deposited individually on a rigid support and subsequently conveyed from said location by means of a conveying means with suction devices in the direction of a charging funnel or a pulling up device. As a result of this, sacks slide from the support and sag in a downward direction. This leads to the sack reaching the pulling up device at an unfavourable angle, said pulling up device being arranged rotatably around a horizontal axis. In the case of sacks with gussets it frequently happens as a consequence of the folded gussets that only the lower wall of the sack sags, whereas the upper wall, due to the folded gussets, tends to arch, and, as a consequence of this, said upper wall bridges the increasing distance between the front edge of the support and the suction devices of the conveying means. This leads to a very uneven opening of the gussets and furthermore to problems with gripping of the sacks by means of the pulling up device which should grip the sacks symmetrically.
Such symmetrical gripping, however, by means of the pulling up device, said pulling up device being mostly arranged by straddling spoons engaging into the sack opening and pressing the gussets in an outward direction, is the prerequisite for pulling up the sack concentrically about the charging funnel. This is essential for a wrinkle-free closing of the filled sack by means of a machine.